EP 1729097 B1 20190508 - PHOTOELECTRIC ENCODER
Title (en)
PHOTOELECTRIC ENCODER
Title (de)
FOTOELEKTRISCHER CODIERER
Title (fr)
CODEUR PHOTO ELECTRIQUE
Publication
Application
Priority
- JP 2005004924 W 20050318
- US 80463604 A 20040319
Abstract (en)
[origin: US2004173737A1] A displacement measuring device including a scale, and an optical readhead including an index pattern and a light receiving element is provided. A bright/dark pattern arising from a scale grating is detected by the readhead to measure displacement. In various embodiments, a magnification of the pattern is adjusted by the spacing between at least a lens element, aperture element, and detection plane of the readhead. An aperture can be designed to provide a diffraction-limited telecentric imaging configuration that filters an image of the scale grating to provide a sinusoidal intensity pattern that supports highly interpolated measurements. An aperture dimension, selected in relation to the grating pitch and other parameters, can provide a desirable combination of readhead operating characteristics including one or more of a desired depth of field; degree of spatial filtering; and optical signal power.
IPC 8 full level
G01D 5/347 (2006.01); G01D 5/36 (2006.01); G01D 5/38 (2006.01); G02B 13/22 (2006.01)
CPC (source: EP US)
G01D 5/34715 (2013.01 - EP US); G01D 5/36 (2013.01 - EP US); G01D 5/38 (2013.01 - EP US)
Citation (examination)
- DE 2300562 A1 19730719 - JENOPTIK JENA GMBH
- CHRISTIAN BERGER: "Design of telecentric imaging systems for noncontact velocity sensors", OPTICAL ENGINEERING, vol. 41, no. 10, 20 September 2002 (2002-09-20), pages 2599 - 2606, XP055022475, DOI: 10.1117/1.1504105]
Designated contracting state (EPC)
AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IS IT LI LT LU MC NL PL PT RO SE SI SK TR
Designated extension state (EPC)
AL BA HR LV MK YU
DOCDB simple family (publication)
US 2004173737 A1 20040909; US 7186969 B2 20070306; CN 100451559 C 20090114; CN 1934422 A 20070321; EP 1729097 A1 20061206; EP 1729097 A4 20080227; EP 1729097 B1 20190508; JP 4838117 B2 20111214; JP WO2005090923 A1 20080522; US 2007018084 A1 20070125; US 2007215797 A1 20070920; US 7435945 B2 20081014; US 7570433 B2 20090804; WO 2005090923 A1 20050929
DOCDB simple family (application)
US 80463604 A 20040319; CN 200580008863 A 20050318; EP 05721111 A 20050318; JP 2005004924 W 20050318; JP 2006511235 A 20050318; US 47548106 A 20060626; US 59910505 A 20050318